Fibroblasts dismantle contractile machinery

This proposal asks whether aging human skin can end wound contraction while its fibroblasts, connective-tissue cells that pull on surrounding material, remain alive and mobile. It proposes that activating YAP, a cell-regulatory protein, permits a brief pulse of executioner caspases, protein-cutting enzymes, to cleave the cell’s force-generating machinery. The predicted sequence is cleavage, sustained loss of pulling force, survival and restored mobility after wound closure, without persistent proliferation. Matrix tension, the physical pull in the surrounding material, may influence the outcome. A decisive test would block executioner caspases and measure whether force persists despite YAP’s usual transcriptional response.